Direct data reading with index (KEY=)

This program illustrates the 'Direct Access' or index-based reading technique in a SAS^© DATA step. It creates two temporary datasets (x and y), one of which is indexed. The third step performs a join where, for each row of x, SAS^© attempts to directly retrieve the corresponding row in y via the index, displaying the return code _IORC_ for diagnostic purposes.

Data Analysis

Type : CREATION_INTERNE

All data (tables x and y) are dynamically generated in the script using loops and random functions (uniform, ranuni).

1 Code Block

DATA STEP Data

Explanation :
Generation of source table 'x' with 3 iterations (i from 0 to 2).

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1	DATA x ;
2	DO i=0 to 2 ;
3	j=round(uniform(i)*10) ;
4	put _all_ ;
5	OUTPUT ;
6	END ;
7	RUN ;

2 Code Block

DATA STEP Data

Explanation :
Generation of lookup table 'y' with immediate creation of an index on variable 'i'.

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1	DATA y(index=(i)) ;
2	DO i=1 to 4 ;
3	j=round(ranuni(i)*3) ;
4	DO k=1 to j ;
5	put _all_ ;
6	OUTPUT ;
7	END ;
8	END ;
9	RUN ;

3 Code Block

DATA STEP Data

Explanation :
DATA step reading 'x' sequentially and accessing 'y' via index 'i' (KEY=i). Displaying _IORC_ allows checking for index lookup success.

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1	DATA z ;
2	SET x(in=in_x) ;
3	SET y(in=in_y) key=i ;
4	put _iorc_= _all_ / ;
5	RUN ;

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